This gives Amazon an extra leg up on smart-home tech and complements existing services that make ordering items from its website easier.

This synergy is what the e-commerce giant does best, and it's a signal to other retailers that it will continue to innovate in this space.

Amazon is acquiring Ring, a startup that specializes in smart-camera-equipped doorbells for dwellings.

At a reported acquisition price north of $1 billion, Ring provides another suite of in-home smarts that both complement and extend Amazon's capability. It also fits in well with Amazon's existing obsession with adding value to its core online-shopping service.

When the company first announced the launch of its in-home delivery service, Amazon Key, it had developed only the camera for it. It had to partner with existing smart-lock makers to create the kits it is currently selling to interested customers.

But Ring's doorbells are equipped with cameras and audio equipment, and they can easily work with voice-enabled smart-home devices to add to that experience and take it to the next level.

Alerts could tell you when the camera notices a delivery person outside your house, and an extra camera could provide more security for the whole operation. You can also chat with the delivery people themselves and answer their doorbell ring remotely. From there, you could tell them to just leave the package, or take it around the side of the house for safe-keeping.

Amazon CEO Jeff Bezos hinted at acquisitions like this one in the company's most recent earnings release.

"Our 2017 projections for Alexa were very optimistic, and we far exceeded them. We don't see positive surprises of this magnitude very often — expect us to double down," Bezos said in a prepared statement.

As Amazon becomes more central to the burgeoning smart-home market, moves that fuse tech and retail will only become more important for the company.

"The trifecta of Alexa, Echo, and Prime should enable Amazon to further penetrate the consumer, expand Prime membership and retail spending patterns, while widening the company's consumer competitive moat with the Ring acquisition putting further fuel in this smart home engine for Amazon," GBH Insights analyst Daniel Ives wrote in a note to investors.

Ring gives Amazon a boost to both its still-central e-commerce business and its burgeoning smart-home business. Amazon did this before with Alexa and Echo, and it's continuing that trend with Ring.

That synergy is Amazon doing what it does best — bringing together two seemingly disparate sectors in new and interesting ways to provide a competitive edge and new services for consumers.